The quality of wine is not only dependent on the characteristics of the wine grapes and there are many other factors that directly influence the character of wine produced. One of the most significant problems during the harvesting process is the collection of material other than grapes along with the actual berries. This material, often referred to as MOG, includes stems, canes and leaves. Stem tannins are quite different from skin tannins and can result in wine with unwanted astringency.
It is well known in the wine industry that MOG can result in a reduction in body and volume of the wine and increase perception of rough tannins, harsh astringency and bitterness. For this reason wineries require fruit free of MOG before it can be placed in the fermenting tanks. Furthermore, many large wineries stipulate in their processing agreements with smaller wineries that they can reject fruit that is in their opinion unsuitable for processing or is contaminated by MOG.
Consequently, sorting tables have been used by wineries to manually remove the MOG. Sorting tables in the past were a simple rectangular horizontal table that accommodated around six people who manually remove the MOG. The tables were not designed for a high crush rate and significantly slowed the harvesting process. However, the tables gave winemakers more control over the quality of grapes placed in the fermentation tanks by eliminating unwanted MOG.
Most large wineries now have sophisticated systems of sorting tables. These tables are usually associated with a destemmer and are tilted at an incline so that the fruit moves slowly toward the hopper. Most manufacturers make tables to accommodate 8 to 12 people, however, some systems are known to accommodate over 20 people. As the reader will appreciate this process is very labour-intensive which results in increased cost of production. This makes many of these systems not commercially viable for smaller wineries.
Despite the costs associated with the removal of MOG, one of the latest trends in winemaking is putting more resources in sorting grapes. Mainstream premium producers are becoming more interested in sorting systems to increase their quality of wine. Likewise, wineries in the lower end of the premium segment of the wine industry are beginning to use procedures once only used by ultra-premium producers.
Systems that are attached to mechanical harvesters have been developed to remove MOG during the harvesting process. These systems incorporate a series of conveyers that separate the berries from the MOG. As the harvested material passes along an inclined separation conveyer the berries are separated from the MOG. The berries are then transported to the hopper and the MOG is deposited back onto the ground as mulch. The difficulty with this system is that it can not account for different operating conditions and different grape varieties. If the harvested material is not allowed to remain on the separation conveyer for a sufficient period of time the berries may be deposited onto the ground along with the MOG. On the other hand, if the harvested material remains on the separation conveyer for an extended period blockage may occur. This is particularly relevant on undulating ground or where grape varieties that typically grow in tight clusters are being harvested. Other factors that influence the degree of difficulty of separating the grape berries from the MOG are the size of the grapes and the time at which the grapes are harvested, for instance for the production of chardonnay the grapes are picked green.
It is an object of the present invention to provide for a MOG remover that overcomes at least some of the aforementioned problems or provides the public with a useful alternative.
It is a further object of the present invention to provide for a MOG remover used with fruit harvesters, such as a grape harvester, that can accommodate different operating conditions.